The invention relates to inhibitors of enzymes that catalyze phosphoryl transfer and/or that bind ATP/GTP nucleotides, compositions comprising the inhibitors, and methods of using the inhibitors and inhibitor compositions.
Many diseases states are characterized by the uncontrolled proliferation and differentiation of cells. These diseases states encompass a variety of cell types and maladies such as cancer, atherosclerosis, restenosis, and psoriasis. Uncontrolled signaling due to defective control of protein phosphorylation has been implicated in a number of diseases and disease conditions, including, for example, inflammation, cancer, allergy/asthma, diseases and conditions of the immune system, disease and conditions of the central nervous system (CNS), cardiovascular disease, dermatology, and angiogenesis.
The inhibitors and compositions comprising them are useful for treating or modulating disease in which phosphoryl transferases, including kinases, may be involved, symptoms of such disease, or the effect of other physiological events mediated by phosphoryl transferases, including kinases. The invention also provides for methods of making the inhibitor compounds and methods for treating diseases in which one or more phosphoryl transferase, including kinase, activities is involved.
Phosphoryl transferases are a large family of enzymes that transfer phosphorous-containing groups from one substrate to another. By the conventions set forth by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (IUBMB) enzymes of this type have Enzyme Commission (EC) numbers starting with 2.7.-.- (See, Bairoch A., The ENZYME database in Nucleic Acids Res. 28:204-305 (2000)). Kinases are a class of enzymes that function in the catalysis of phosphoryl transfer. The protein kinases constitute the largest subfamily of structurally related phosphoryl transferases and are responsible for the control of a wide variety of signal transduction processes within the cell. (See, Hardie, G. and Hanks, S. (1995) The Protein Kinase Facts Book, I and II, Academic Press, San Diego, Calif.). Protein kinases are thought to have evolved from a common ancestral gene due to the conservation of their structure and catalytic function. Almost all kinases contain a similar 250-300 amino acid catalytic domain. The protein kinases may be categorized into families by the substrates they phosphorylate (e.g., protein-tyrosine, protein-serine/threonine, histidine, etc.). Protein kinase sequence motifs have been identified that generally correspond to each of these kinase families (See, for example, Hanks, S. K.; Hunter, T., FASEB J. 9:576-596 (1995); Kinghton et al., Science, 253:407-414 (1991); Hiles et al., Cell 70:419-429 (1992); Kunz et al., Cell, 73:585-596 (1993); Garcia-Bustos et al., EMBO J., 13:2352-2361 (1994)). Lipid kinases (e.g. PI3K) constitute a separate group of kinases with structural similarity to protein kinases.
Protein and lipid kinases regulate many different cell processes including, but not limited to, proliferation, growth, differentiation, metabolism, cell cycle events, apoptosis, motility, transcription, translation and other signaling processes, by adding phosphate groups to targets such as proteins or lipids. Phosphorylation events catalyzed by kinases act as molecular on/off switches that can modulate or regulate the biological function of the target protein. Phosphorylation of target proteins occurs in response to a variety of extracellular signals (hormones, neurotransmitters, growth and differentiation factors, etc.), cell cycle events, environmental or nutritional stresses, etc. Protein and lipid kinases can function in signaling pathways to activate or inactivate, or modulate the activity of (either directly or indirectly) the targets. These targets may include, for example, metabolic enzymes, regulatory proteins, receptors, cytoskeletal proteins, ion channels or pumps, or transcription factors. Initial interest in protein kinases as pharmacological targets was stimulated by the findings that many viral oncogenes encode structurally modified cellular protein kinases with constitutive enzyme activity. These findings pointed to the potential involvement of oncogene related protein kinases in human proliferatives disorders. Subsequently, deregulated protein kinase activity, resulting from a variety of more subtle mechanisms, has been implicated in the pathophysiology of a number of important human disorders including, for example, cancer, CNS conditions, and immunologically related diseases. The development of selective protein kinase inhibitors that can block the disease pathologies and/or symptoms resulting from aberrant protein kinase activity has therefore generated much interest.
Cancer results from the deregulation of the normal processes that control cell division, differentiation and apoptotic cell death. Protein kinases play a critical role in this regulatory process. A partial non-limiting list of such kinases includes ab1, Aurora-A, Aurora-B, Aurora-C, Akt, bcr-abl, Blk, Brk, Btk, c-Kit, c-Met, c-Src, CDK1, CDK2, CDK4, CDK6, cRaf1, CSF1R, CSK, EGFR, ErbB2, ErbB4, ERK, Fak, fes, FGFR1, FGFR2, FGFR3, FGFR4, FGFR5, Fgr, Flt-4, Flt-1, FER, Frk, Fyn, Hck, IGF-1R, INS-R, Jak, KDR, Lck, Lyn, MEK, p38, PDGFR, PIK, PKC, PLKs, PYK2, Ros, Tie1, Tie2, Trk, Yes and Zap70. In mammalian biology, such protein kinases comprise mitogen activated protein kinase (MAPK) signaling pathways. MAPK signaling pathways are inappropriately activated by a variety of common disease-associated mechanisms such as mutation of ras genes and deregulation of growth factor receptors (Magnuson et al., Seminars in Cancer Biology 5:247-252 (1994)). Therefore the inhibition of protein kinases is an object of the present invention.
Polo-like kinases (PLKs including PLK1, PLK2, PLK3 and PLK4) are serine/threonine protein kinases that have been implicated in human cancer, such as colon, breast and other solid tumors. Polo-like kinases (also referred to as PLKs) are believed to be involved in protein phosphorylation events that regulate the cell cycle. Specifically, PLK1 may play a role in controlling the accurate segregation of chromosomes during mitosis. Misregulation of the cell cycle can lead to cellular proliferation and other abnormalities. In human colon cancer tissue, PLKs have been found to be overexpressed (See, Barr et al in Nat. Rev. Mol. Cell. Biol. 5: 429 (2004); van Vugt et al in Oncogene, 24: 2844 (2005)). PLK1 as an attractive candidate molecule for targeted tumor therapy is reported recently (see Takai et al in Oncogene, 24:287 (2005); McInnes et al in Current Topics in Med. Chem., 5: 181 (2005)).
There is a continued need to find new therapeutic agents to treat human diseases. Protein kinases, specifically but not limited to Polo-like Kinase (PLK), are especially attractive targets for the discovery of new therapeutics due to their important role in hyperproliferative disorders; cancer (e.g., solid tumors, leukemias, lymphomas, non-small cell lung cancers and esophageal carcinomas); inflammatory and autoimmune diseases (e.g., psoriasis, alopecia; multiple sclerosis; colitis, arthritis, Alzheimer's disease, glomerulonephritis and wound healing); chemotherapy agent-induced alopecia and mucositis; cardiovascular diseases (e.g., stenoses, arterioscleroses, restenoses, and hypertrophy); viral, bacterial, fungal and/or parasitic infectious diseases (e.g., cytomegalic infections, herpes, hepatitis B and C, Karposi's sarcoma, HIV diseases); nephrological diseases (e.g., glomerulonephritis); chronic and acute neurodegenerative diseases (e.g., Huntington's disease, amyotrophic lateral sclerosis, Parkinson's disease, AIDS dementia, Alzheimer's disease, ischemias of the brain and neurotraumas); skin diseases (e.g., psoriasis); bone diseases; the protection of proliferating cells (e.g., hair, intestinal, blood and progenitor cells) from DNA damage caused by radiation, UV treatment and/or cytostatic treatment; and other diseases. Certain inhibitors of PLK are disclosed in WO 2007/095188. The present invention provides inhibitors of PLKs, including some having reduced susceptibility to multi-drug resistance.